Originally Posted by Alvyn
its run
26psi all day long, every day for 7 months and never had a problem with them. i tried some champion c57's? and had nothing but missfires gapped at 6thou! thought it was a bit odd...
WAS the miss fire mainly on tick over by any chance?
If so that's because you had the WRONG plugs in with 26psi I CANT see u with MORE than 350 bhp so you SHOULD have had Champion 59's in it NOT the c57's
ps: LOADS of people just put in Champion c57 and get NOTHING but miss fire NORMALLY on tick over and THEN slag off the plugs WHEREAS it's because they have wrongly been inform about the plug range USE c59's upto 400 bhp and after that c57's to 500/550 bhp!
car ran fine on tickover, only had problems at peak boost. the car's still on a t3, so it really shouldn't do that, surely? like i said, i stuck a set of motorcraft plugs back in it and it's been perfect since!